The need to move increasing amounts of data from one location to another at higher transfer rates has lead to the development of several standard approaches. One of these approaches is known as Asynchronous Transfer Mode (ATM) in which 53-byte cells are used to move data packets from one location to another.
The currently available large ATM switches are in the 20 to 160 gigabits per second (Gbps) range. These switches are actually composed of a number of small, single stage switches ganged together to form a larger switching matrix, referred to as a multistage switch. The typical transfer rate for the small, single stage switching elements is typically around 5 Gbps.
When many smaller switches are combined together to produce a large switch, inefficiencies result. For example, a multistage switch requires as much as six times as much switching fabric as a larger single stage switch for the same amount of capacity.
In addition, the currently available single stage switches are primarily configured with eight inputs and eight outputs. Some currently available single stage switches are configured with eight inputs and eight outputs. Typically, the data rates for the inputs are usually at either the 155 Mbps OC-3 rates or the 622 Mbps OC-12c rates, where OC indicates an optical signal. The Synchronous Optical Network (SONET) hierarchy is based on a fundamental unit which is equal to 51.84 Mbps. For example, an OC-1 nomenclature implies a 51.84 Mbps rate, and an OC-3 input implies a 1.5 Mbps rate (3*51.84 Mbps).
The 8.times.8 fabric size that is typically used is convenient for two reasons. First, there are a number of products available which implies lower costs. Secondly, the serial data rates involved force optical fiber interconnects between the basic switching fabric and the other cards, and fiber optic transmitters and receivers are available to support the 8.times.8 configuration.
What is needed is a larger packet switch module which will decrease the size of the resulting switching equipment by having simpler control capabilities.